CAUTION: CONTAINS PLOT SPOILERS!
Philjolet, your first two comments were from the same episode of NIGHT GALLERY. The gist of the story was that a visiting Colonel had the "hots" for the plantation owner's wife, so he hired some locals to put this caterpillar in the husband's ear, which would result in a horrible death. Unfortunately, the locals mixed up the bedrooms, and put it in the Colonel's own ear. He went through a week of such agony, that even his intended victim felt compassion. The punch line was that after a week of suffering, the doctor told him that there was some good news. The insect had eaten directly through his brain, and emerged from the other ear, a one-in-a-million chance, as no one had ever previously survived. When questioned further, since the doctor appeared hesitant, the Colonel was informed that the insect was a female which had laid eggs inside his brain...HORRIBLE SCREAM...FADE TO PORTRAIT...ROD SERLING'S EPILOGUE.
The second show was a TWILIGHT ZONE (this one was written by Rod) called "To Serve Man". First Aired: March 2, 1962. It starred the late Richard Kiel as the alien. He played "Jaws" in the James Bond movies.
Douglas_schroeder, that was STAR TREK 2, THE WRATH OF KHAN, starring Ricardo Montalban (..."Genuine Corinthian Leather!"...from the Chrysler Cordova TV commercials) as well as FANTASY ISLAND.